Fluid compressor



Sept. 30, 1930. o. slMMEN 1,776,933 Y FLUID COMPRESSOR' Filed Jan. 3. 1929 2 Sheets-Sheet l Aw; #im fdl-,wai

ATTE! F\N Sept. 30, 1930. v 0, slMMN 1,776,933'

FLUID coMPm-:sson A Filed Janu, 1929- ZjSheQtS-Sheet 2 ZNx/EIJTUA:

i BY

@WQ 0m, 01m *EM f-ATmRN EVS Patented Sept. 30, 1930 l f .y UNITEDSTATES OSCAR SIMMEN, or ERLAGH, SWITZERLAND, ASSIGNOR TOTHE FIRM SutzER FRERES SOCIT ANONYME, or WINTERTHUR, SWITZERLAND "FLUID COMPRESSOR i Application led ,iJ'anuary' 3, 182.9, Serial No. 330,077, Vand in Switzerland January 31, 192'8.

This invention relates to fluid compressors of the piston type and more particularly those intendedfor use Ain small refrigerating machines.

A fluid compressor according to this invention comprises a casing adapted to receiveV movement atfvarying velocity, such as pendulum movement, and an inertia mass so. mounted wlthm the casing as not 'toparticle` pate or to participate only part-ially in this movement, thev relative movementbetween-the casing and the inertia mass being converted not directly, but indirectly into the working stroke of the compressor piston or pistons.

Preferably each cylinder of the compressor is secured to the casingso aS to participate in the movement thereof, the inertia mass being arranged withinthe casing so as to act on each piston in accordance `with the relative movement between the casing and the inertia mass.

between the casing 'and the inertia mass is transmitted to each piston by means of a cammounted on the inertia mass and acting upon the piston which lis heldin engagement ywith the cam surface by means of a return springl or the like.

Thus the point on the inertia mass which of the casing so that only the inertia mass is exposed to any accidental irregularities in relative movement, whilst the piston stroke, being dependent on the movement of a cam Y surface, is relieved from any such irregularities.

Alternatively the piston may be connected to the inertia member as by means of a connecting rod, this arrangement having the advantage that the necessity for a return spring on the piston is obviated.

Two alternative constructions of fluid compressor according to this invention together with some modifications are illustrated by way of example in the accompanying drawings, in which s Conveniently the relative movementl is mounted on a hollow spindle 5 and towhich is secured a cam 6. Within thecasing land rigidlysecured toeit is a 'compressor-cylinder 7, the pressure or delivery chamber 8 of which isconnected through'a suction valve 9 tothe suction chamber 11 and through a delivery valve 10 tothe delivery branch 12. The com-A pressor thus draws fluid in in the direction indicated by the arrowsv 13 and 14,'4 and `delivers in the direction of the arrow 15.

The piston lwhich is provided at its outer end with a roller 17 is pressed outwards by the spring' 18.v The `pivot pin 19 transmits to the-casing 1 the oscillating movement eected by means off a connecting rod 20 in the direction of the doubleiarrow 21. The inertia member 4 isprovided with two studs 22 which are so connected by means ofsprings 23 to the casing 1 that the cam 6 is forced into the central position as shown in Figure 2. The operation of the compressor is then as'follows.

1 During the Working a pendulummotion is transmitted tofthe casing 1 and thus to the compressor cylinder. 17, the freely mounted.

inertia mass 4 takingpart inthis motion onlywith-distortiom The mass 4 owing toi its inertiaand under the action of the springs 23 will oscillate lightlyabout the central po.-

sition shown in Figure 2 and will describe the are indicated by zinFigure 3, the casing `l with the compressor cylinder 7 willdescribe the arc-indicated by b, so that the compressor cylinder 7 lwillv be moved to and fro between the end positions a: andy shown inFigure 3. Consequently the piston 16 will be moved up and down in the'cylinder I andwill perform compressor work: i

Thus the delivery stroke of thefcompressor FFICE elevation onthe line is exactly determined without being limited by stops and the only accidental movement is that of the inertiamass 4. The are Z; is, however, calculated in such a manner as to ensure that the piston I6 of the compressor can in any case travel through the prescribed stroke. The cam may be either of symmetrical or unsymmetrical form and may have a surface as shown in chain lines in Figure 2, this having the advantage that when the compressor is in its central position it is maintainedV in the state of stable equilibrium and further that the starting of the compressor is facilitated as in such a case the cam is forced into the central position not only by the springs 23 but also by the working reaction, whilst in the case of a positively constructed cam the working reaction has the tendency to push the cam out of the central position.

In the modified construction shown inrFgure 4, a rod 35 is used in place of a cam. In those constructions in which a cam is employed both the upper and the lower dead centre positions of the compressor or of the compressors are exactly determined but when rods are employed only the upper dead centre position is exactly determined, whilst-the lower dead centre position depends on the amplitude of the relative deflections between the inertia mass and the casing which however, in most cases is only of secondary importance.

In the construction shown in Figure 5, two compressor cylinders 25 are mounted in the casing 24. The inertia mass 2G in the form of a pendulum bob is mounted by means of a rod 27 pivoted at the centre of rotation 28 of the compressor and the cam 29 connected to the rod 27 acts on rollers 30 of double-armed levers 3l to which the piston rods are secured. IVhen an oscillatory movement is transmitted to the compressor casing Q4 by the rod 32 in the direction of the double arrow 33 the inertia mass 26 and the cam 29'will not take part in the said movement, or will take part in it only to a limited extent so that the roll ers 30 and the transmission levers 3l will by reason of their movement relativelyto the cam, transmit the working movement to the two pistons 34. The fluid to be delivered will then be drawn in through the suction valves 36 and expelled through the delivery valves 37. lWith this arrangement the compressor when in its central position will be maintained in a state of stable equilibrium, starting of the compressor being thereby facilitated as above set forth.

The indirect transmission of the Working movement of the pistons by means of cams or rods has the advantage of making it possible without the use of stop devices to maintain exactly the upper and in some cases also the lower dead centre position of the compressor piston.

I claim:

l. In a fluid compressor of the piston type the combination with a swingable casing of a piston compressor being in a iXed connection to the casing, an inertia mass yieldingly arranged within the casing and a cam mounted on the inertia mass for transmitting the relative movement between the casing and 'the inertia. mass to the driving parts of the piston compressor.

2. In a iuid compressor of the piston type the combination with a swingable casing of a piston compressor having a number of cylinders and being in a lined connection to the casing, an inertia mass yieldingly arranged withinthe casing and a number of cams mounted on the inertia mass and each trans mitting the relative movement between the casing and the inertia mass to the piston o a compressor cylinder.

3. In a fluid compressor of the piston type the combination with a swingable casing of a piston compressor having a number of cylinders and being in a liXed connection to the casing, an inertia mass yieldingly arranged within the casing and a number of cams mounted on the inertia mass and each transmitting the relative movement between the casing and the inertia mass to the piston of a compressor cylinder, the central part of the cams being so formed that stable equilibrium of the inertia member corresponds to the central position of the compressor.

4. In a fluid compressor of the piston type, the combination with a swingable casing ol a piston compressor, an inertia mass in the form of a pendulum bob arranged to swing relatively about the center of oscillation of the casing and to participate only partially in the swinging of said casing, and means for transmitting the relative movement between the casing and the inertia mass to the driving parts of the piston compressor.

In testimony whereof I have aiiiXed my signature.

OSCAR SIMMEN. 

